Macular Degeneration: Barak A

Barak A, Hauser D, Yipp P, Morse L, Leigh B, Kubo D, Goldberg Z, Earle J, Handa JT. · Department of Ophthalmology, UC Davis, Sacramento, CA, USA. · Br J Radiol. · Pubmed #16110105 links to  free full text

Abstract: Effective treatment for neovascular age-related macular degeneration (AMD) is currently limited. Radiation therapy, a therapeutic approach with known antiangiogenic properties, has been investigated as a modality to prevent severe visual loss in AMD. Most of the studies using external beam radiation employed <25 Gy to the whole eye, which is below the dose of radiation that is toxic to the retina and optic nerve ( approximately 50 Gy and approximately 59 Gy, respectively). Stereotactic fractionated external beam radiation (St-EBR) is a method that allows radiation to be delivered to a small, defined area. We investigated the effects of St-EBR in incremental doses up to 40 Gy on neovascular AMD. Patients with clinical signs and fluorescein angiography demonstrating neovascular AMD, visual acuity (VA) better than 20/400 and ineligible for laser treatment (MPS criteria) or who refused to have laser photocoagulation were enrolled in the study. Each patient was treated with radiation at incremental dosages from 20 Gy to 40 Gy. After completion of the radiation course, all patients were followed-up at 3 and 7 weeks and 3, 6, and 12 months. Best-corrected VA (ETDRS), slit-lamp and fluorescein angiographic evaluations were performed at each visit. 94 eyes of 89 patients were treated from October 1997 to April 2000. The VA was 0.82+/-0.35 before treatment, 0.83+/-0.36 at 6 months, and 0.89+/-0.33 at 12 months. No patients suffered any significant acute side effects. No significant benefits in either VA or in membrane size were derived from increasing the doses of radiation. Our results are consistent with trends of a palliative benefit of radiotherapy in neovascular AMD and support further investigation of radiotherapy. Since there is no evidence that therapeutic effectiveness is dose dependent, our data provide no justification for potentially dangerous escalations in radiation dosage for treating neovascular AMD.

Goldstein M, Loewenstein A, Barak A, Pollack A, Bukelman A, Katz H, Springer A, Schachat AP, Bressler NM, Bressler SB, Cooney MJ, Alster Y, Rafaeli O, Malach R, Anonymous00107. · Department of Ophthalmology, Tel-Aviv Medical Center, Israel. · Retina. · Pubmed #15805906 No free full text.

Abstract: PURPOSE: To compare the preferential hyperacuity perimeter (PHP) with an Amsler grid in detection of age-related macular degeneration (AMD). METHODS: Patients underwent refraction, visual acuity examination, PHP, Amsler grid examination, and macular photography. RESULTS: One hundred fifty patients participated in the trial. Of 19 eyes with neovascular AMD, 19 (100%) were positive on the PHP, and 10 (53%), on the Amsler grid. Of 27 eyes with geographic atrophy, 26 (96%) were positive on the PHP, and 12 (44%), on the Amsler grid. Of 20 eyes with intermediate AMD, 14 (70%) were positive on the PHP, and 4 (20%), on the Amsler grid. Of 51 eyes with early AMD, 21 (41%) were positive on the PHP, and 4 (8%), on the Amsler grid. Of 33 eyes with no AMD, 6 (18%) were positive on the PHP, and none, on the Amsler grid. Thus, 80 (68%) of 117 patients with AMD had a positive PHP, while 30 (26%) had positive results of Amsler grid examination (P < 0.001, McNemar test). CONCLUSION: The PHP had greater sensitivity, although with a relatively high rate of false-positive results for healthy individuals, than the Amsler grid in detecting AMD-related lesions.

Loewenstein A, Malach R, Goldstein M, Leibovitch I, Barak A, Baruch E, Alster Y, Rafaeli O, Avni I, Yassur Y. · Department of Ophthalmology, Tel-Aviv Medical Center, Tel-Aviv, Israel. · Ophthalmology. · Pubmed #12750099 No free full text.

Abstract: PURPOSE: To investigate a method that uses hyperacuity, the Macular Computerized Psychophysical Test (MCPT), to evaluate the central macular visual field in patients with age-related macular degeneration (AMD). DESIGN: Prospective case-control study of a diagnostic test. PARTICIPANTS AND CONTROLS: One hundred eight eyes of 108 Patients with AMD and 51 eyes of 51 age-matched patients with no retinal disease. Patients with AMD included 32 (30%) patients with choroidal neovascularization (CNV), 23 (21%) with geographic atrophy (GA), 35 (32%) with AMD with high-risk characteristics (HRC), and 18 (17%) with early AMD with non-HRC. TESTING: Each subject underwent the MCPT, in which a virtual line composed of dots (white dots on a black background, maximal contrast) is flashed across different macular loci to a perifoveal radius of 7 degrees. Patients' responses were recorded and automatically analyzed using a specific algorithm developed before the onset of the study. All patients also underwent a supervised Amsler grid examination on the encounter before or after the MCPT in random order. MAIN OUTCOME MEASURES: Distortion, scotoma, or blurring perceived by the patient after a swift change of fixation was considered positive on the MCPT. Any perception of distortion, scotoma, or blurring was considered positive on the Amsler grid. RESULTS: Of the 32 patients with CNV, 30 (94%) were found positive on the MCPT and 11 (34%) were found positive on the Amsler grid. Of the 23 GA patients, 21 (91%) were found positive on the MCPT and 7 (30%) were found positive on the Amsler grid. Of the 35 HRC patients, 28 (80%) were found positive on the MCPT and 3 (9%) were found positive on the Amsler grid, and of the 18 early AMD with non-HRC patients, 8 (44%) were found positive on the MCPT and 3 (17%) were found positive on the Amsler grid. Of the 51 controls, 3 (6%) were positive on the MCPT and 1 (2%) was positive on the Amsler grid. CONCLUSIONS: The MCPT was superior to the Amsler grid in detecting AMD-related lesions in this cohort. Studies are underway to determine whether the MCPT is feasible for home monitoring to provide early detection of progression to CNV.

Barak A, Regenbogen M, Goldstein M, Loewenstein A. · Department of Ophthalmology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel. · Isr Med Assoc J. · Pubmed #16544727 links to  free full text

Abstract: BACKGROUND: Diabetic macular edema causes visual loss in almost one-third of diabetic patients. There is currently no treatment for the accompanying cystoid foveal changes. OBJECTIVES: To assess the clinical outcome, i.e., change in visual acuity, in patients treated with steroids for long-standing diabetic macular edema with foveal cystoid changes. METHODS: In the ophthalmology department of a tertiary care university-affiliated medical center and the ophthalmology service of a health management organization, 46 diabetic subjects (56 eyes) who had diabetic macular edema with cystoid foveal changes received one intravitreal injection of 4 mg triamcinolone acetonide. RESULTS: The mean baseline (pre-injection) visual acuity of 0.21 increased to 0.31 and 0.48 at 1 and 3 months, respectively, after which it decreased to 0.33 at 6 months. The mean intraocular pressure was 15.07 mmHg at baseline, 15.83 at day 1, gradually rising to 17.16, 18.38 and 18.57 mmHg at 1, 3 and 6 months respectively. Three patients suffered immediate visual decline after the injection. CONCLUSIONS: Intravitreal triamcinolone acetonide may be a therapeutic option for long-standing diabetic macular edema with foveal cystoid changes.

Shahar J, Avery RL, Heilweil G, Barak A, Zemel E, Lewis GP, Johnson PT, Fisher SK, Perlman I, Loewenstein A. · Department of Ophthalmology, Tel-Aviv Medical Center, Israel. · Retina. · Pubmed #16508424 No free full text.

Abstract: PURPOSE: Intravitreal bevacizumab (Avastin; Genentech Inc., San Francisco, CA) is a new treatment for age-related macular degeneration. The aim of this study was to evaluate retinal penetration and toxicity of bevacizumab. METHODS: Ten albino rabbits were injected intravitreally with 0.1 mL (2.5 mg) of Avastin into one eye and 0.1 mL saline into the fellow eye. The electroretinogram (ERG) was recorded after 3 hours, 3 days, and 1, 2, and 4 weeks. The visual evoked potential (VEP) was recorded after 4 weeks. Confocal immunohistochemistry was used to assess retinal penetration. RESULTS: The ERG responses of the control and experimental eyes were similar in amplitude and pattern throughout the follow-up period. The flash VEP responses of the experimental eyes were of normal pattern and amplitude and did not differ from those recorded by stimulation of the control eye alone. Full thickness retinal penetration was present at 24 hours and was essentially absent at 4 weeks. CONCLUSIONS: Bevacizumab was found to be nontoxic to the retina of rabbits based on electrophysiologic studies. Full thickness retinal penetration may explain observed clinical effects of intravitreal bevacizumab. Although it is difficult to directly extrapolate to humans, our study supports the safe use of intravitreal bevacizumab injection.

Goldstein M, Heilweil G, Barak A, Loewenstein A. · Department of Ophthalmolgy, Tel-Aviv Medical center, Sackler School of medicine, Tel-Aviv, Israel. · Eye. · Pubmed #15803179 No free full text.

Abstract: PURPOSE: To describe retinal pigment epithelial tear following photodynamic therapy (PDT) for subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). DESIGN: Retrospective interventional case series. METHODS: A retrospective study in an institutional practice. We describe seven cases of retinal pigment epithelial (RPE) tear, which developed in seven eyes of seven patients following PDT. All eyes had subfoveal CNV secondary to AMD. RESULTS: Six eyes had occult subfoveal CNV, and one eye had recurrent classic subfoveal CNV. In five patients, the eye that developed the tear was the second eye, whereas the first eye had a disciform scar. In four eyes, the RPE tear developed after one PDT, in one eye the RPE tear developed after the second PDT, and in two eyes the RPE tear developed after the third PDT. In five of seven cases, there was a significant visual deterioration following the RPE tear. CONCLUSIONS: RPE tear is a complication that may occur following PDT in particular when the PDT is applied to an occult subfoveal CNV.

Barak A, Morse LS, Schwab I. · No affiliation provided · Rheumatology (Oxford). · Pubmed #14739469 links to  free full text

This publication has no abstract.